Need advice on losing sight

Not sure if this is Health or Behavior. My cat (about 15 years) has lately been losing her sight. There was no accident or disease, and she's strictly an indoor cat. I know about not moving furniture, but what else can I do to help her? I think she only sees shapes.

I had a younger adult blind female - some of the biggest things are to not move furniture, make sure every time a door is opened you know where she is (she was very curious for being blind & loved to go through doorways), and make sure you know where she is. Blind cats can't see feet coming, so are more likely to get stepped on.

I have a senior kitty who is slowly going blind, and she seems to be adapting very well. She has other cats who can help guide her around.